Glass Bodies a variant-level encyclopedia of vintage lenses and cameras by iwillpat

Biogon T* 21mm f/2.8 (Contax G)

Carl Zeiss · Contax G · 1996 · Biogon — near-symmetrical wide-angle, 9e/7g

Also known as: Contax G Biogon 21mm f/2.8 · Biogon 21mm f/2.8 G · Biogon T* 2.8/21 · Contax G 21mm · Zeiss Biogon 21mm Contax G

Variants & identification

Variant Mount Years Serial ranges Production
Biogon T* 21mm f/2.8 (Contax G) Contax G 1996–2005 — Unpublished — Kyocera released no figures
How to tell them apart (expand)

Biogon T* 21mm f/2.8 (Contax G):

  • 55 mm filter — the only G prime that is not 46 mm; sold with the GF-21 finder
  • Green label required on a G1

Specifications

Formula
Biogon — near-symmetrical wide-angle, 9e/7g
Construction
9 elements / 7 groups
Aperture range
f/2.8–f/22
Min. focus
0.5 m
Weight
200 g
Filter
55 mm
Years manufactured
1996–2005
Country
Japan
Coating
Carl Zeiss T* multicoating

What reviewers say

History

Nine elements in seven groups, 200 grams, a 55 mm filter and a 90° diagonal: the widest autofocus lens in the system, sold from 1996 with its own GF-21 finder because the body’s finder stops at 28mm. It needs the green-label G1 or a G2. Ibraar Hussain, who used one for thirteen years, calls it his most versatile lens and notes that it can, unusually for an ultra-wide, throw a background out of focus at f/2.8.

Like the 28, it is a true Biogon with its rear group deep in the throat, which is why it draws so well on film and so badly on a digital sensor without help; Shige’s M-converted copy and the PCX-filter experiments on the 28 tell that story.

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This history is AI-written, from the sources listed at the foot of the page. Where the record is silent it says so rather than filling the gap — but no human wrote these sentences.

Example photos

Sample photo taken with the Biogon T* 21mm f/2.8 (Contax G)
Contax G2 with the Biogon 21mm f/2.8 and its accessory finder — Ignis, via Wikimedia Commons (CC BY-SA 3.0)

Sample photo wanted — shot with a Biogon T* 21mm f/2.8 (Contax G)? We'd love to feature it (with credit).

Live listings

Asking price, USD: a median of $500 across 38 fixed-price listings on 2026-09-11 (middle half $450–$670). Tracked since 2026-09-10, 2 days: unchanged from $500.

By day
DateMedianMiddle halfListings
2026-09-11$500$450–$67038
2026-09-10$500$450–$67037

Asking prices from the listings scanned, not sales; junk-flagged rows and auction lots excluded; other currencies are not converted.

Show 80 more listings

Listings updated 2026-09-11. Links go to the shop or marketplace that carries the item.

Related: Hologon T* 16mm f/8 (Contax G) · Biogon T* 28mm f/2.8 (Contax G)

Sources (5)

Every page here is assembled from public sources, and the gaps are real ones. If you own this lens, know a serial number I'm missing, or can see where I have it wrong, tell me — corrections, serials and sample photos are all worth having.